Self-braking driving device for an operating shaft



E. E. HENSEL 3,194,366

SELF-BRAKING DRIVING DEVICE FOR AN OPERATING SHAFT July 13, 1965 3 Sheets-Sheet 1 Filed June 11. 1962 INVENTOR 5-16.19 5 Hens el ATTORNEYS July 13, 1965 HENsEL 3,194,366

SELF-BRAKING DRIVING DEVICE FOR AN OPERATING SHAFT Filed June 11, 1962 3 Sheets-Sheet 2.

INV EN TOR ATTORNEYS E. E. HENSEL 3,194,366

SELF-BRAKING DRIVING DEVICE FOR AN OPERATING SHAFT July 13, 1965 3 Sheets-Sheet 5 Filed June 11. 1962 INVENTOR {NE/{7 e2rse/ Jaw A? wkr abwm ATTORNEY United States Patent 3,194,366 SELF-BRAKlNG DRIVING DEVICE FOR AN OPERATING SHAFT Erich Emil Hensel, The Hague, Netherlands, assignor to Hunter Douglas International (Quebec) Limited, Mentreal, Quebec, Canada, a corporation of Qanada I Filed June 11, 1962, Ser. No. 201,475 Claims priority, application Netherlands, June 9, 1961, 265,739 1 Claim. (Cl. 192-8) This invention relates to a self-braking driving device for a Venetian blind, a rolling-shutter or the like, over which there extends an operating shaft driven by a driving device, said driving device comprising a housing accommodating a braking device which becomes operative when the weight of the Venetian blind or the like exercises a torque on the operating shaft and becomes inoperative when the operating shaft is driven by the driving device.

The self-braking driving devices of this kind known so far present the difliculty that they are of complicated construction and, moreover, the locking device does not become operative rapidly enough when the driving device is not driven any longer so that consequently the Venetian blind or the rolling-shutter lowers itself over a considerable distance. The self-braking device according to the invention avoids these difficulties in that said braking device comprises two co-operating parts mounted on the operating shaft and destined to put the braking device into and out of operation, the first part of which being nonrotatable relative to the operating shaft and the second part being rotatable over a small angle relative to the operating shaft and to the first part, said relative rotatory movement of both parts putting the braking device into or out of operation. The self-braking driving device according to the invention presents the additional advantage that it requires little extra space since the majority or all of the parts may be mounted in the head rail of the Venetian blind or the rollingshutter or in the prolongation of said head rail and, moreover, said device may be accommodated at any point in the head rail. A further advantage of the selfbraking driving device according to the invention is that all parts may be of robust construction.

A preferred embodiment of the self-braking driving device according to the invention is characterized in that on the operating shaft there is arranged a tubular part coupled with the driving device, said tubular part being rotatably mounted in the housing and comprising one or more projections engaging with both parts with clearance. The magnitude of this clearance may be easily controlled since this depends upon the dimensions of the projections and the recesses. Since one may select a small clearance the lock-ing device may rapidly become operative.

The braking device may be constructed as a friction coupling of which a wall portion of the housing serves as a friction surface.

A preferred embodiment of the self-braking driving device is characterized in that the surfaces facing each other of both co-operating parts are provided with one or more cams or raised portions having slightly inclined surfaces. These cams are preferably symmetrical so that consequently the self-brakingdevice is adapted to be utilized for driving devices mounted at the left hand side as well as the right hand side of the Venetian blind or rolling-shutter.

The self-braking driving device may also be of such construction that the part which is rotatable over a small angle relative to the operating shaft consists of a disc having at its circumference a plurality of recesses, the

Gal

part which is non-rotatable relative to the operating shaft being constructed as a cage in which a number of rollers corresponding with the recesses of the disc are provided, said rollers being located between the disc and the cylindrical inner wall of the housing.

If desired one or more springs may be provided in the braking device which acts or act directly or indirectly on the part provided with a braking surface. If the braking action is accomplished in that both co-operating parts are clamped in the housing between the cover and the braking surface, these springs are weak springs so that in the non-operative position of the braking device these springs do not exercise an inconvenient braking action.

If this spring or these springs are to supply the braking action, then, of course, these spirngs are strong springs.

The invention will be explained below with reference to the accompanying drawings showing by way of example some embodiments of the self-braking driving d vice according to the invention.

- FIG. 1 shows a longitudial section of the first embodiment of the driving device.

FIG. 2 is a section according to the line i-l-ll of FIG. 1.

FIG. 3 shows a side view of a detail.

PEG. 4 shows a longitudinal section of a second embodiment.

FIG. 5 is a section according to the line VV of FIG. 4.

FIG. 6 is a longitudinal section of a third embodiment.

FIG. 7 shows a fourth embodiment in longitudinal section.

FIG. 8 is a section according to the line VliI-Vlll of FIG. 7.

The self-braking driving device shown in FIGS. 1-3 comprises a housing which is subdivided by a partition wall into two portions 2 and 3. In the bottom 4 of the housing portion 2 there is rotatably mounted a driving end 5 which at its end projecting into the housing portion 2 carries a bevel gear wheel 6. This bevel gear wheel is in engagement with a bevel gear wheel '7 which by means of lips 8 is coupled with :a tubular part 9 mounted in the partition wall 1 and freely rotatable about a shaft 16, this shaft constituting the operating shaft of the Venetian blind, rolling-shutter or similar closing means. This operating shaft is hollow and comprises a groove 12 extending in the longitudinal direction. The tubular part projecting into the housing portion 3 has two projections 13 disposed diametrically relative to one another. These projections 13 engage with arcuate recesses 14 of two parts 15 and 16 of a braking device, of which the part 15 has a friction surface 17 co-operating with -a friction surface 18 provided in the housing portion 3. The surfaces of parts i5 and 16 facing each other each have cams l9 and 2% respectively with slightly inclined flanks which are in engagement with one another and are of symmetrical shape. Consequently this driving arrangement may be provided at the left hand side as well as the right hand side of a Venetian blind or rolling-shutter. Should said cams not be symmetrical, then it would be necessary to design individual self-braking driving devices for the left hand and the right hand side. Part 16 is provided at its inner side with a projection 21 engaging the groove-like recess 12 of the operating shaft it Consequently part 16 cannot rotate about the shaft. Part 15 is being urged by a weak spring 22 towards part 18. This spring abuts at its other end against a cover or closure plate 23 of the housing portion 3, said cover being secured by means of a screw thread in the housing port-ion 3. In this cover there is inserted a tubular part 24 belonging to part 1.6, said tubular part 24 serving as a bearing for the shaft Hi. This shaft is also mounted in the tubular part 9 as well as in the end wall 25 of the housing portion so that consequently this operating shaft 'issatisfactorilysup- 15 and16. Part 16 engages with'itsrprojection 21 with tate the shaft 1%; Consequently part 16 will rotate so that the cams 24) will run on the cams 19 and part16 lar part 9 which'via the projections 13 drives both parts i V the groove 12 of the operating shaft 1% so that the latter 5 f is rotated. As a consequence thereofthe blind or 'rolling--- shutter will be raised or lowered according to the direc-' urges the. friction surface 17 of part 15 against the frictionsurface 18 provided in the housing portion 3, since" part 16 abuts: with its rear face against the inner. face of cover 23. However, part 16 cannot rotate freely relative to part 15 since the projections 13 engage with the re-Y end edges of the recesses 14 thus rendering impossible a further rotation of both parts. By giving the recessesa 'In the embodiment according to FIGSL4 and- 5 the projections 13 of the tubular part 9 engage with'recesses V 14- of a disc 26 having four flattened surfaces Z'lfof concesses 14 provided in both parts- I'fpart '16 rotates -relative to partlfi the projections 13' will 'abut against the v cavearcuate shape. Rollers 28 'co-operate with these flat- V cage 29 abuts against a rubberblock 30. j V

The above-described device operatesas follows:

Ifthe driving end 5 is rotated the gear wheels and 7 are driven. The. gear wheel 7 drives the tubular part 9; which, via the projections 13, drives the disc 26 and the cage 29: The disc-26 engages 'by means of a projection shutter will be raised or lowered according to the direc' 31 and 32 of the recesses 14.. The 'disc 26 therefore rotates over a small angle relative to the cage 29 and con- -tened surfaces, said rollers being adapted to rotate in a: cage 29 mounted on'the shaft it These rollers co-oper-v ate with the inner wall of the housing 1. The

21 with the groove 12 of the operating shaft 10 sojthat the'latter is rotated. Consequently the blind or rollingin sequently the rollers 28 move over the flattened surfaces .7 V

' 2'7 and are clamped between the inner wall of the housing land the disc 26. thus preventing a further rotation of the shaft 10.

The embodiment .accordingzto 6 is shown in the a.

position in which the brake is operative. In this embodi-L 'rnent there is provided on the cylindrical surface ofthe tubular part 9 a projection 33 with clearance in recesses 5,

34 and 35 of two co-operating parts 36 and 37 so that the tubular part 9 and the parts 36 and 3'7 may rotate over-a small angle relative to each other. Parts36 and 37are arranged in the prolongation of each other and their faces;

facing each other; comprise cams'orraised portions 33 and 39 respectively. Part 36 is providedwith a braking surface co-operating with a friction surface provided in. a partition wall Mlof-the housing 1; Part 37 has a tubular extenclosur'eplate or cover 43., This extension is locked in the groove with abolt 44. Between thecover 43 and the 3 .part 36'there is provided. a spring 45;

- The above-described embodiment. operatesas follows? Ifthe; driving endS is rotated the gear wheels 6 and 7' 'RoBERro; nronnom nxamz a 1 directionin whichthedriving endisrotated. f

If thedriving ,end5 is. notdriven any longerlthefveight f of the 1 blind or therolling-shutter:will 5 cause the shaft 10 )5 to rotate:. The part'37-,jvvhich with its prrojectionc lz is] located in thefgroove of theoperating shaft lfl is'itakens along so; that conseqnentlyithe cams or raisedpportions i 39 of this part rotate relative' torthecams orfpar'ts36 and; said part 36 is urged against the partitionlwalliso, that the it device, assumes the-position 'shownYin 6. in which a V i. the braking surfaces o'f.:the braking jdevicje iare fir mly' pressedvtogether thusnpreventing a?zfurtherirotationabf I i the operating shaftq.

FIGSJ7 and '8 "present a corntnodated in a groove ofthe ,hollowshajft 10x Between the part 48 andfa cover So'therehas been provided 'f 7 a spring 51' urging thepart ddagainst' the partitioqwall 40 of the hous'ingl; The'tubularpartB isipr ovided again i with projections arranged withpclearance lira ICTCCLS SfOf the part '48. The 'd'evicjeis'showngin the ;position inwhich the operating shaft is braked; I When the driving end 5 is rotated thegear'wheels6 andjl lwillrotate thetubular part9 so thatconsequently the projections 46 are moved'in theirecess 47- and pressthe part1; the. braking surface in'the housing .1 so'thattheblindb rollin -shutteris lowered'or r'aisedaccording to the direc .tion'inwhichthe driving, end 5 iisprotated; V V f 3 departingfrorn the. scope; of the invention; i

Iclaima I V A self-braking} driving device; for j a Venetian blind, a. rolling shutter, and the like; comprisinganioperating shaft and a driving means, said shaft being drivinglyj-conriected' to said driving means said device comprising a-ho'usingj and' a braking nie'ans' within said housing, {said b'r aking means comprising two co-operating' partsimounted lon; v, said operating shaft, a braking surface on one of isaid parts and abralging surface onsaidhousingpsaidsurfaces co operating with each other, the other of said parts'be-Q- ing non-rotatably' mounted relative to said-shaft, said one} of said co operating p'ar'ts'bing rotatable only overa small angle relative'to said shaftand relative to said'other 1 V part, 'a V tubular.-rnen ber; mountedjonusaid" shaft? and rotatahly n1ounted j on isaid vhousing saidmrnberiib'eirig drivingly coupled to saidfdriving njearis andihaving lat least one projection, recesses: in' bothfs'aid 'co;operating.; parts, said projection extending intd-saidmrecesses ja ndfi- L said recesses providing a certain arnount' of clearance bettween "said projection andfsaid"co operatingfparts, 'said j Q clearance allowing "foracertainian1ount of lost motion, r between said projection and. saidjco-op'eratingparts; mu ,tually' engaging icarn faces. on said .co-operating parts; said carn faces including elevations and depressions. i j I ttsm fi dhy h Eraininer ,1; l UNITED STATES PATENTS;

;, 903,805' 11 /08: Wuest 1,634,861 7/27 Weymann; 2,561,159 7/51'f Walton,., 2,783,861 3/57.:slungles 2,971,619., 7/511 'Kosloff DAVID JJWILLIAMQWSKY, aims}; ExL-ain 7 fourth, embodiment inipartz t .Inlthis embodimentthereareprovidedron'the rnantle of' V the tubular partf9 two 'projections 1 '46, J46 I'Co o'perating'; with recesses :47 of a parted provided with a' braking surface',.said part '48 (having a;proje ctioni49 which is ac-w. 

